Commit c31783ee authored by David Hildenbrand's avatar David Hildenbrand Committed by Andrew Morton
Browse files

mm/pagewalk: don't trigger test_walk() in walk_page_vma() 

As Peter points out, the caller passes a single VMA and can just do that
check itself.

And in fact, no existing users rely on test_walk() getting called.  So
let's just remove it and make the implementation slightly more efficient.

Link: https://lkml.kernel.org/r/20221021101141.84170-7-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 93fb70aa

include/linux/pagewalk.h

+2 −0
Original line number Diff line number Diff line
@@ -27,6 +27,8 @@ struct mm_walk; 
 *			"do page table walk over the current vma", returning

 *			a negative value means "abort current page table walk

 *			right now" and returning 1 means "skip the current vma"

 *			Note that this callback is not called when the caller

 *			passes in a single VMA as for walk_page_vma().

 * @pre_vma:            if set, called before starting walk on a non-null vma.

 * @post_vma:           if set, called after a walk on a non-null vma, provided

 *                      that @pre_vma and the vma walk succeeded.

mm/pagewalk.c

+0 −7
Original line number Diff line number Diff line
@@ -526,18 +526,11 @@ int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, 
		.vma		= vma,

		.private	= private,

	};

	int err;



	if (!walk.mm)

		return -EINVAL;



	mmap_assert_locked(walk.mm);



	err = walk_page_test(vma->vm_start, vma->vm_end, &walk);

	if (err > 0)

		return 0;

	if (err < 0)

		return err;

	return __walk_page_range(vma->vm_start, vma->vm_end, &walk);

}